Hookless Ankle-Based Inversion Device

ABSTRACT

A device used for ankle-based inversion therapy and which does not require hardware is described in this document. It allows the user to be suspended in an inverted posture from their ankles while being supported by an auxiliary mounting bar. The design of this device is presented in this document as an alternative to traditional hook-based gravity boots.

BACKGROUND OF THE INVENTION

Inversion therapy is a method for achieving a decompression of themusculoskeletal system. Spinal traction occurs when the head is at alower plane of elevation than the feet, thereby reversing the normalgravitational loading that occurs while standing or sitting.

The degree of traction is measured by the angular displacement of thehead from the horizontal plane that exists while lying flat in a proneposition. The range of traction is therefore zero to ninety degrees,with maximum traction occurring while suspended orthogonal to the levelsurface below.

Gravity boots are an established method for enabling an inverted posturethrough ankle-based suspension. Traditional gravity boot designs usehooks which connect to an elevated horizontal bar. This requiresattaching a pair of gravity boots to the ankles, and then raising thefeet to the elevation of the bar in order to enter the inverted posture.

SUMMARY OF THE INVENTION

The purpose of the device described is to provide a means for suspensionby the ankles in a fully inverted position and thereby achieve maximumtraction. Pull-up bars, of the type used in gymnastics and fitnessactivities that are designed to support the static loads generated byhuman body weight, are the intended support structures for this deviceto be used in conjunction with.

The device described can be constructed from synthetic polymer webbingthat has a rated tensile strength which determines the safe working loadthat can be supported. It is sewn together, according to the describeddesign, using synthetic polymer thread that is also rated in terms ofthe load-bearing capacity of each stitch (pounds/stitch). Thiscombination of materials provides a means to predict the maximum loadbearing capacity of this device when assembled, and thereby incorporatelarge safety factors.

Advantages to using the device described for ankle-based inversiontherapy are:

-   -   1. The device adds no weight to the ankles. When the feet are        raised up toward the mounting bar, no extra load must be        carried, which translates to less effort required.    -   2. The device described, when mounted to a horizontal support        bar, has handles that are significantly lower in elevation than        the bar itself. This makes it unnecessary to reach all the way        to the bar when exiting the inverted position, because the        device has extended handles that are closer to the hands    -   3. The load tension of applied body-weight causes the device to        close around the ankles, due to its self-tightening nature. It        is therefore not possible to fall or slip out of the device        while in the inverted position.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 depicts the device described, with numbers referring to theindividual components outlined in the claims section.

FIG. 2 depicts two devices attached to a horizontal mounting bar andsecured around both ankles while in use.

FIG. 3 depicts a pair of devices, showing the directional differencebetween the left and right version.

FIG. 4 depicts an as-built test model assembled from webbing and thread.

FIG. 5 depicts an as-built test model with a toe-hold loop of adjustableposition relative to the main device body and a handle composed ofseparate finger loops.

FIG. 6 depicts an as-built test model based on the design shown in FIG.1.

FIG. 7a shows the handle augmented with surrounding material to providemore grip surface.

FIG. 7b shows the handle composed of individual finger loops.

FIG. 8 depicts the self-encircling part of the primary loop inisolation, with the black region representing a protective coveringattached on the inside to prevent abrasion. The sheath could be made ofdurable and flexible plastic-polymer, and would eliminate frictioncontact between layers of webbing when the device is opened and closed.The sheath concept shown is a tubular single piece of material, and thewebbing would be inserted through it prior to assembly.

DETAILED DESCRIPTION OF THE INVENTION

Directions for Use:

Entry:

-   -   1. Verify that the left and right versions of the device are        oriented correctly (the left should form a lowercase “D” letter        shape, and the right should form a lowercase “B” letter shape,        as shown in the figures).    -   2. Attach a pair of devices to the horizontal support bar, by        placing the mounting loop over the bar and then threading the        body of the device through the loop as shown in the figures.    -   3. Slide the main loop into its fully open position, by moving        the self-encircling portion of the main loop upward. This        provides the maximum open surface area for the foot to be        inserted through.    -   4. Verify that the handle and its extension are within the        interior region of the sliding portion of the main loop, as        shown in the figures.    -   5. Grasp the handle of the left-foot device with the left hand,        and grasp the right-foot device handle with the right hand, and        verify that all connections are secure by lifting feet off the        ground and applying body-weight load to the pair of devices.    -   6. Raise feet upward to the bar while holding device handles,        and lean back simultaneously to minimize the amount of        upper-body effort used.    -   7. Position the device around each ankle by inserting the left        and right foot through the opening provided by the main loop of        each device while using the big toe of the opposite foot in        conjunction with the toe-hold loop to further control the        device.    -   8. While still holding the handles, tighten each device around        the ankles by pulling both feet downward.    -   9. Release the handles and move backward into a fully inverted        posture.

Exit:

-   -   1. Raise the torso upward until the handles are within reach.    -   2. Grasp the left handle with the left hand, and the right        handle with the right hand. Apply load to each handle by pulling        downward as if the weight of the upper body were being supported        by the handles and their extensions.    -   3. Shifting the static load application point, as described in        the previous step, allows the main loop of the device to be        relaxed and expanded. While briefly supporting the majority of        body weight with the handles, use the big toe of the opposite        foot in conjunction with the toe-hold loop to pull the main loop        off of each ankle and allow the feet to exit.    -   4. Using a controlled movement, while still holding the handles        securely, lower the feet to the ground. Do not release the        handles until footing is secure.

Optional but Recommended Steps Prior to Use:

-   -   1. Cover the mounting bar with tape or protective cloth, to        prevent the abrasion of webbing or stitching by exposed rough        metallic surfaces.    -   2. Wear a pair of tube socks with the toe box cut open to        provide a protective padding barrier between skin and device        webbing.

Instructions for Assembly:

The size of the device can be scaled depending on foot-size and anklecircumference. The relative dimensions of the major components, as shownin the figures and described in the claims, are critical. The handleloop must be large enough to accommodate the hand, the main loop must belarge enough when fully expanded to accommodate the through-passage ofthe foot, and the handle extension must be of sufficient length for theextension to remain inside of the self-encircling sliding region of themain loop when it is fully contracted around the ankles. The mountingloop must also be large enough to encircle the supporting bar structureand allow the whole device to pass through.

An ideal construction material is polyester webbing, with 2″ width usedfor the main loop and body of the device, and 1″ width used for allother components. The width-reducing attachment interface between themain loop and the handle extension maximizes the surface area of theseams connecting these two components.

Webbing used for assembly is heat sealed at exposed ends to preventfraying. Heat-treated ends are hard and brittle and must be folded overonce and sewn in place to prevent contact abrasion.

Sheaths to prevent webbing abrasion can be installed on sections of thedevice that are exposed to friction. These sections can include theself-encircling, sliding region of the main loop, the mounting loop, andthe handle itself. The sheath can be made from durable fabric by sewinga tubular structure that surrounds the section of webbing beingprotected. The webbing would be inserted through the pre-fabricatedtubular coverings prior to sewing. Single-piece molded polymer unitscould be used, if the plastic material were sufficiently durable andflexible.

The device can be constructed according to the drawings and descriptionsusing a sewing machine. The as-built test models of the device depictedin FIGS. 4-6 use reinforced box-tack stitching patterns at all majorconnection points.

1. A device, which suspends a human in an inverted physical position bythe ankles, comprising: a) a primary webbing loop, which can changecircumference based on applied tension, where one end of said primaryloop encircles the width of the webbing and is moveable along itslength, and the other end is fixed at the top of the device; b) awebbing loop connected to the fixed end of the primary loop, formounting the device to external support structures; c) a webbing loophandle, with an extension which exists within the interior of themoveable end of the primary loop, and which connects to the primary loopdirectly below the mounting loop attachment point, with said extensionbeing of sufficient length to remain inside of the moveable end of theprimary loop during its entire range of motion; and d) a loop connectedto the ankle-surrounding region of the primary loop, which provides atoe-hold for moving the device with the opposite foot.
 2. The device ofclaim 1, in which a width-reducing interface loop is attached to theprimary loop and linked to the handle extension.
 3. The device of claim1, in which a hardware ring is connected to the fixed end of the primaryloop and acts as the mounting loop component.
 4. The device of claim 1,in which a material other than webbing, but with the physical propertiesto conform to the described topological configuration, is used forconstruction of the whole device or any of its components.
 5. The deviceof claim 1, in which the handle is augmented with padding or encased intubing.
 6. The device of claim 1, in which material sheaths coverfrictional contact areas.
 7. The device of claim 1, in which permanentlyattached or removable padding is added to the ankle-surrounding regionof the device.
 8. The device of claim 1, in which the handle iscomprised of separate finger-loops.
 9. The device of claim 1, in whichthe handle and its extension are comprised of two separate pieces andlinked together.
 10. The device of claim 1, in which the toe-hold loopis free to move in relation to the primary loop via sliding action.